M.S. Thesis Presentation by Joseph C. Crawford III
Tuesday, May 15, 2001

(Dr. Jonathan Colton, advisor)

"Injection Failure of Stereolithography Molds"

Abstract

The stereolithography (SL) process has grown much beyond its original use as a rapid prototyping technique.  For instance, stereolithography has been used to create molds for injection molding.  Compared to traditional methods, stereolithography can build complex mold geometries easily and rapidly.  Although the mold life of stereolithography tools is short compared to traditional metal molds, the time savings in creating these prototypes can be measured in weeks.

 This thesis investigates ways to predict thermal and mechanical loads in stereolithography tools used for injection molding focusing on the deflection and failure of the mold during the filling and holding phases of the injection molding cycle.  To accomplish this, a method for analyzing stereolithography molds was developed using analytic and finite element methods.  This method allows a mold designer to predict whether the stereolithography mold will fail and provide a range of how much a mold feature will deflect.  Lastly, processing guidelines are proposed to obtain the longest mold life possible from stereolithography tools.